Russian President Vladimir Putin yesterday warned that Moscow would not remain indifferent to NATO's "muscle-flexing" and said Russia's nuclear forces would be ready for an adequate response to any aggressor.

Putin, speaking to top generals less than two weeks before December 2 parliamentary elections, said the NATO military alliance had built up its forces close to Russia's borders.

"We see that military resources of certain states and members of the NATO alliance are being built up right by our borders and in contravention of previously reached agreements," Putin said in remarks shown on state television.

He said strategic nuclear forces - which control Russia's long-range nuclear missiles - should be ready "to deliver a swift and adequate response to any aggressor".

NATO is viewed with great suspicion in Russia, where Kremlin officials say expansion eastwards into the Baltic states and Central Europe shows the alliance is being used by the United States to threaten Russian interests.

Putin said Russia's suspension of the Conventional Forces in Europe Treaty, a key arms treaty limiting forces in Europe, was one way to counter NATO's "muscle-flexing".

"We are not going to fulfil anything unilaterally - our partners did not ratify the treaty and some did not even sign it," Putin said, adding sarcastically: "It was a nice affair."

Russian generals say the issue of flank limits, which restrict Moscow's ability to deploy heavy armor on parts of its own territory, must be solved if Russia is to return to the treaty.

Russian proposals to set up a single missile defense system under joint control have not had an answer from the West, Putin said.

He praised the military potential of the Shanghai Cooperation Organization (SCO), a regional grouping of Russia, China and four Central Asian states which held joint military exercises in August in Chebarkul in the Urals.

"The growing defense potential of the SCO was shown in practice at the Chebarkul range," Putin said.

At the August exercises, Putin said security threats had forced Russia to resume regular airborne bomber patrols across the world, bringing back memories of the Cold War.

Putin has been keen to show off his close ties with the military, visiting a nuclear submarine, flying a bomber and calling for better wages for soldiers.